Mylan was slapped Monday with a class-action racketeering lawsuit that claims the company overcharged patients as part of an illegal scheme to secure sales, CNBC reported.

The suit, filed in U.S. District Court in Seattle, alleges the "skyrocketing" list price of EpiPen was the result of the drugmaker's payments of rebates to pharmacy benefit managers — including CVS Caremark, Express Scripts and Optum Rx — which handle prescription drug benefit programs for insurance plans.

The suit noted when EpiPen prices were increasing most dramatically, other companies tried to introduce competing devices. But those companies never succeeded in displacing Epipen's market dominance because Mylan paid pharmacy benefit managers higher rebates, the suit said.

The suit claims violations of consumer protection laws of all U.S. states, as well as a violation of the Racketeer Influenced and Corrupt Organization Act.